function correct_layout(titel) {
  /* Aktuellen Item im Navigationsmenü hervorheben */
  document.getElementById(titel).className='navi_self';
  
  var len = 0;
  var navigation_height = document.getElementById('left').offsetHeight;
  var content_height = document.getElementById('content').offsetHeight;
  /* Höhe für content-Bereich korrigieren */
  content_height += 20;
    
  if (content_height > navigation_height) { 
    len = content_height; 
  }
  if (navigation_height > content_height) {
    len = navigation_height;
  }
  
  len += "px";
  document.getElementById('content').style.height = len;
  document.getElementById('left').style.height = len;
}